My emeter has never had an issue -- it runs from the high voltage prescaler that has the power supply for the emeter built in, not from the 12 volt auxiliary battery or main DC-DC (when I get that added) and even with the main battery bank suffering from horrible sag (agms going away next week, just picked up the new lithium bank yesterday) it's never had an issue. I'd give a thumbs up on that prescaler/power supply for it.
Z On Tue, Nov 5, 2013 at 9:55 PM, Cor van de Water <[email protected]> wrote: > Paul, > > Apparently someone was afraid that the DC/DC was too noisy to run the > Emeter without problem, > so they added an elaborate filter - causing this problem in the process. > Just remove the diode, if needed reduce the resistance value. The cap > after the resistors > will clamp all noise anyway, but this way you are gaining back at least > 0.7 to 1V. > I presume that it is not easy to jack the DC/DC output up one volt? > If I am not mistaken, the Emeter was designed for 12V *or* 24V house > batteries in an RV, > so it can take up to 30V (recharging 24V lead-acid batteries) by design, > so it can easily > live off a 15V supply instead of exactly 12V. > > Cor van de Water > Chief Scientist > Proxim Wireless Corporation http://www.proxim.com > Email: [email protected] Private: http://www.cvandewater.com > Skype: cor_van_de_water XoIP: +31877841130 > Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203 > > ________________________________ > > From: [email protected] on behalf of Paul Wallace > Sent: Tue 11/5/2013 8:13 PM > To: [email protected] > Subject: Re: [EVDL] Anyone have issues with Emeter resetting with > > > > Lee, > very strange circuit topology for the implementation of the DC/DC in the > USElectricar with the Datel DC/DC. The DC/DC input has a fuse added, that > looks good. The output, however, is very strange. the common output pin > of the DC/DC goes directly to the Emeter negative lead. The positive DC/DC > output pin is routed through a diode, and then two 5.1ohm resistors in > parallel (2.55ohms) and finally to the positive input of the emeter. There > is also a 1000uf 16vdc electrolytic cap on the output. No wonder I see > such odd input voltage to the emeter when it is drawing current. The diode > drop alone is at least 0.6v. > > Paul Wallace > > > From: Lee Hart <[email protected]> > > To: Electric Vehicle Discussion List <[email protected]> > > Subject: Re: [EVDL] Anyone have issues with Emeter resetting with > > noise from controller > > Message-ID: <[email protected]> > > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > > > Paul Wallace wrote: > >> My Link-10 is going through a reset at random times when the inverter > >> is switched to drive. I've looked down to see the display switched > >> to blinking volts more than once. > > > > This is usually caused by the Link-10 momentarily losing its 12v power. > > If the power dips below about 10.5v, the display blanks. When the power > > goes back up above this, the display will be blinking and it will have > > lost certain values (like amphours). > > > >> The Emeter is powered by an isolated DC/DC converter. > > > > Where does this DC/DC converter get its power? From the car's 12v > > system, or from your DC pack voltage? The pack voltage probably dips > > under load. This dip either directly makes the Link-10's DC/DC drop out, > > or it causes the car's main 12v DC/DC converter to momentarily sag, so > > the 12v falls, and this makes the Link-10's DC/DC sag. > > > >> I wasn't anticipating too much noise would make it through at a > >> magnitude great enough to cause this sort of problem. The current > >> shunt wires are twisted together from the shunt until they reach the > >> Deutch connector, along with the voltage sense wires. > > > > The shunt, and the prescaler wiring won't cause this sort of reset > > problem. They can make the display blank; but they won't cause the meter > > to reset and forget the amphour reading etc. > > > >> Since the front panel says Link-10, I'm thinking that it should have > >> the EV filter already installed. Has anyone added extra filtering to > >> mitigate noise getting into the E-meter? > > > > It may, or may not have the EV filter inside. Physically, the filter is > > a 1000uF 35vdc electrolytic capacitor across the Link-10's power input, > > plus a 1N4001 diode and 3.3 ohm resistor in series. Bad ASCII schematic > > (view with fixed width font like Courier). > > > > +12v power____|\|____/\/\________+12v power to Link-10 > > from DC/DC |/| 3.3ohm | > > 1N4001 resistor _|_+ > > diode ___ 1000uF 35vdc capacitor > > common________________________|__common (NOT ground!) > > > > Without the filter, it only takes a few millisecond power dip to reset > > the meter. With the filter, it takes more like a half-second power dip. > > > > You can add this filter externally yourself. It won't hurt to add it > > again, even if it's already inside. A schottky diode (1N5818 etc.) is a > > slightly better choice than the 1N4001. There is no upper limit for the > > capacitance; bigger is in general better. > > -- > > Any intelligent fool can make things bigger, more complex, and more > > violent. It takes a touch of genius, and a lot of courage, to move > > in the opposite direction. -- Albert Einstein > > -- > > Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm > > > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: not available > Type: application/ms-tnef > Size: 8357 bytes > Desc: not available > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20131105/9b6a94b3/attachment.bin > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -------------- next part -------------- An HTML attachment was scrubbed... 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